What value should I use for host in a kubernetes ingress manifest?

Question

I have this yaml for an Ingress:

kind: Ingress
apiVersion: extensions/v1beta1
metadata:
  name: app
  namespace: ingress-controller
... omitted for brevity ...
spec:
  rules:
    - host: ifs-alpha-kube-001.example.com
      http:
        paths:
          - path: /
            pathType: ImplementationSpecific
            backend:
              serviceName: service-nodeport
              servicePort: 80
          - path: /
            pathType: ImplementationSpecific
            backend:
              serviceName: service-nodeport
              servicePort: 443
status:
  loadBalancer:
    ingress:
      - {}

In the above I set ...

    - host: ifs-alpha-kube-001.example.com

That host just happens to be one of my nodes. I have three nodes. I am pretty certain that this incorrect. The ingress works but if I shutdown ifs-alpha-kube-001 the ingress stops working. What should I set host if I want a high availability cluster?

Thanks

Update: I tried out duct_tape_coder's suggestion but I still must be doing something wrong.

I need to be able to access web servers on both port 80 and 443 so I create two "single service" ingresses.

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: port-80-ingress
  namespace: ingress-controller
spec:
  backend:
    serviceName: port-80-service
    servicePort: 80

... and ...

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: port-443-ingress
  namespace: ingress-controller
spec:
  backend:
    serviceName: port-443-service
    servicePort: 443

And I deleted my old ingress. But I still only able to access the web server on my first node, ifs-alpha-kube-001, and not ifs-alpha-kube-002 and ifs-alpha-kube-003. I verified that my web server is running on the pods.

Update II:

Ok I tried this instead:

kind: Ingress
apiVersion: extensions/v1beta1
metadata:
  name: app2
  namespace: ingress-controller

... omitted ...

spec:
  rules:
    - http:
        paths:
          - path: /
            pathType: ImplementationSpecific
            backend:
              serviceName: service-nodeport
              servicePort: 80
          - path: /
            pathType: ImplementationSpecific
            backend:
              serviceName: service-nodeport
              servicePort: 443
status:
  loadBalancer:
    ingress:
      - {}

$ kubectl describe ingress app2 --namespace=ingress-controller
Name:             app2
Namespace:        ingress-controller
Address:
Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
  Host        Path  Backends
  ----        ----  --------
  *
              /   service-nodeport:80 (10.233.119.22:80,10.233.123.33:80,10.233.125.29:80)
              /   service-nodeport:443 (10.233.119.22:443,10.233.123.33:443,10.233.125.29:443)
Annotations:  Events:
  Type        Reason  Age   From                Message
  ----        ------  ----  ----                -------
  Normal      CREATE  13m   ingress-controller  Ingress ingress-controller/app2
  Normal      CREATE  13m   ingress-controller  Ingress ingress-controller/app2
  Normal      UPDATE  12m   ingress-controller  Ingress ingress-controller/app2
  Normal      UPDATE  12m   ingress-controller  Ingress ingress-controller/app2

And deleted all other ingresses. But still I can only access http on host ifs-alpha-kube-001 with the weird twist ... if I execute:

curl -L --insecure https://ifs-alpha-kube-001.example.com -vvvv

I get a ton of output about redirection.

> GET / HTTP/2
> Host: ifs-alpha-kube-001
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/2 302
< date: Tue, 23 Jun 2020 15:52:28 GMT
< server: Apache/2.4.39 (Unix) OpenSSL/1.0.2k-fips mod_wsgi/4.7.1 Python/3.6
< location: https://ifs-alpha-kube-001/
< content-length: 211
< content-type: text/html; charset=iso-8859-1
< strict-transport-security: max-age=15768000
<
* Ignoring the response-body
* Connection #1 to host ifs-alpha-kube-001 left intact
* Maximum (50) redirects followed
curl: (47) Maximum (50) redirects followed
* Closing connection 0
* Closing connection 1

What is going on here?

Update III

Here are the services I have set up:

$ kubectl get service --namespace=ingress-controller  -o wide
NAME                      TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                                     AGE     SELECTOR
haproxy-ingress           NodePort    10.233.23.21   <none>        80:30032/TCP,443:30643/TCP,1936:30302/TCP   6d4h    run=haproxy-ingress
ingress-default-backend   ClusterIP   10.233.5.224   <none>        8080/TCP                                    6d5h    run=ingress-default-backend
service-nodeport          NodePort    10.233.3.139   <none>        80:30080/TCP,443:30443/TCP                  5d18h   k8s-app=test-caasa-httpd,pod-template-hash=7d79794567

I believe I have tied the service-nodeport service to my ingress app2.

Answer 1

Don't set a host and it'll be available on all hosts, https://kubernetes.io/docs/concepts/services-networking/ingress/. You can also designate a hostPort for it to be available on a specific port on all hosts. I would recommend doing that, then using an external load balancer/proxy to hit the ingress hostport on all nodes.